The QUIET Instrument
ArXiv 1207.5562 (2012)
Authors:
QUIET Collaboration, C Bischoff, A Brizius, I Buder, Y Chinone, K Cleary, RN Dumoulin, A Kusaka, R Monsalve, SK Naess, LB Newburgh, G Nixon, R Reeves, KM Smith, K Vanderlinde, IK Wehus, M Bogdan, R Bustos, SE Church, R Davis, C Dickinson, HK Eriksen, T Gaier, JO Gundersen, M Hasegawa, M Hazumi, C Holler, KM Huffenberger, WA Imbriale, K Ishidoshiro, ME Jones, P Kangaslahti, DJ Kapner, CR Lawrence, EM Leitch, M Limon, JJ McMahon, AD Miller, M Nagai, H Nguyen, TJ Pearson, L Piccirillo, SJE Radford, ACS Readhead, JL Richards, D Samtleben, M Seiffert, MC Shepherd, ST Staggs, O Tajima, KL Thompson, R Williamson, B Winstein, EJ Wollack, JTL Zwart
Abstract:
The Q/U Imaging ExperimenT (QUIET) is designed to measure polarization in the Cosmic Microwave Background, targeting the imprint of inflationary gravitational waves at large angular scales (~ 1 degree). Between 2008 October and 2010 December, two independent receiver arrays were deployed sequentially on a 1.4 m side-fed Dragonian telescope. The polarimeters which form the focal planes use a highly compact design based on High Electron Mobility Transistors (HEMTs) that provides simultaneous measurements of the Stokes parameters Q, U, and I in a single module. The 17-element Q-band polarimeter array, with a central frequency of 43.1 GHz, has the best sensitivity (69 uK sqrt(s)) and the lowest instrumental systematic errors ever achieved in this band, contributing to the tensor-to-scalar ratio at r < 0.1. The 84-element W-band polarimeter array has a sensitivity of 87 uK sqrt(s) at a central frequency of 94.5 GHz. It has the lowest systematic errors to date, contributing at r < 0.01. The two arrays together cover multipoles in the range l= 25-975. These are the largest HEMT-based arrays deployed to date. This article describes the design, calibration, performance of, and sources of systematic error for the instrument.
